First of all be aware of the compartments the blood will flow through such as the left and right atria and ventricles. Note the bicuspid, tricuspid and semi lunar valve positions.Blood entering the right atrium is coming from the body with no oxygen, blood entering the left atrium is oxygen filled blood that has just passed through the lungs, ready to be sent through the rest of the body. Deoxgenated blood enters the right atria then follows the pathway of the right ventricle, pulmonary trunk, lungs, then the right atria and ventricle, before it is pumped through the aorta to the rest of the body